FOAM (SHEET) EXTRUSION OF EXTERNALLY PLASTICIZED CELLULOSE ACETATE (CA)

摘要

Today, oil-based polystyrene (PS) is one standard material used for producing thermoformable extruded foam sheets with physical blowing agents (PBA). PS is a non-biodegradable polymer based on non-renewable resources. Cellulose acetate (CA) is a biodegradable polymer based on renewable resources. Moreover, CA exhibits mechanical properties and heat distortion resistance which is comparable to those of PS. This contribution presents recent results of foam sheet extrusion of externally (physically) plasticized CA using different types of chemical and physical blowing agents. In the case of chemical foaming, the decomposition temperature as well as the decomposition products has a significant influence on the foaming process (e.g. thermal degradation of the biopolymer) and the final properties of the CA foam sheets. The foam densities and foam ratios as well as the mechanical properties of the foam sheets were investigated and compared with a standard XPS foam sheet.